Grenade

ABSTRACT

As shown in FIG.  1,  a grenade comprising a case  3,  a sabot  2,  and a forward part in the form of a nose cone  1  incorporating a pay load  4,  the case  3  incorporating a suitable firing charge, the sabot  2  and the forward part being snap fitted to one another, and the sabot having a projection or projections  7  on its periphery arranged to engage rifling in the barrel of a grenade firing weapon when the grenade is being fired so that such engagement imparts spin to the sabot; 
         the grenade being characterized in that the projection or projections  7  is/are formed from a suitable synthetic substance (eg Teflon™) substantially different to the substance used to form the periphery of the sabot  2  from which the projections  7  extend.

FIELD OF INVENTION

This invention relates to a grenade. A particularly preferred form of the invention relates to a practice grenade.

BACKGROUND

It is known to use propelled grenades as weaponry in the context of modern warfare, one such example being that described in published New Zealand patent specification No. 514921 to the present applicant. It is also known to use propelled practice grenades charged with a suitable dye for training combat forces in the art of warfare, an example of which is described in published New Zealand patent specification No. 328369, also to the present applicant. Such grenades are designed to be fired from a suitable rifle so that they can reach targets faster and more efficiently than if thrown by hand. It is desirable that in the process of firing such grenades they engage rifling within the barrel of the rifle being used. This engagement imparts spin to the grenade as it is fired. It is accordingly an object of at least one form of the present invention is to provide a grenade with rifling engaging means.

The term “comprise”, “comprises”, “comprised”, or “comprising”, if and when used herein, should be interpreted non-exclusively,—eg to mean “consisting of or including”.

SUMMARY OF THE INVENTION

According to one aspect of the invention there is provided a grenade comprising a case, a sabot, and a forward part, the case incorporating a suitable firing charge, the sabot having a projection or projections on its periphery arranged to engage rifling in the barrel of a grenade firing weapon when the grenade is being fired so that such engagement imparts spin to the sabot, and the forward part incorporating a pay load;

-   -   the grenade being characterized in that the projection or         projections is/are formed from a suitable synthetic substance         substantially different to the substance used to form the         periphery of the sabot from which the projection(s) extend.

Optionally the projection or projections on the one hand, and the rest of the sabot on the other, are moulded each from a dissimilar polymeric substance.

Optionally the projection or projections are substantially formed from Teflon.

Optionally the payload is a quantity of dye, a plurality of projectiles, or an explosive, etc.

BRIEF DESCRIPTION OF THE DRAWINGS

Some preferred forms of the invention will now be described by way of example and with reference to the accompanying drawings, of which:

FIG. 1 is a longitudinal cross section view of a practice grenade,

FIG. 2 is a longitudinal cross section view of a sabot forming part of the grenade, and

FIG. 3 shows detail of rifling engaging projections forming part of the sabot.

DETAILED DESCRIPTION

Referring to FIG. 1, the grenade comprises a nose cone 1, a medial sabot 2, and a tail end case 3. The cone 1 contains a quantity of marking dye 4, and is preferably snap fitted to the sabot 2. The sabot 2 has a cavity 5 housing a weight 6 immediately behind the dye 4. The weight 6 is positioned to encourage the nose cone 1 to land nose down when the grenade is fired from a grenade launching rifle. The case 3 contains a suitable grenade firing charge and is snap fitted to the sabot 2.

Preferably the nose cone 1 is formed from a suitable synthetic substance, eg a suitable plastic, and has radial lines of weakness. The lines of weakness cause the cone 1 to rupture more readily and release the marking dye 4 when it has hit a target as the result of the grenade being fired. The dye marks the place of impact so that trainees can see how accurate they have been when firing such grenades for training purposes.

Referring to FIG. 2, the sabot 2 has a series of projections 7 extending around a medial part of its circumference. These are also known as “drive lands” and they take the form of a series of ridges and valleys. The drive lands are arranged so that when the grenade is fired they engage the rifling within the barrel of the rifle being used so as to impart spin to the sabot and cone. The drive lands are characterized in that they are formed (eg injection moulded) from a dissimilar polymeric material to that used to form (eg mould) the rest of the sabot. Preferably the drive lands are formed from Teflon, a suitable polyethylene polymer, or a suitable polypropylene polymer. The rest of the sabot may be formed from ABS plastic or some alternative suitable substance.

An advantage of creating drive lands from a dissimilar polymeric material to the rest of the sabot is that a softer or less abrasive material can be used for the drive lands, and a more structurally rigid material used for the rest of the sabot 2. Using a softer material for the drive lands avoids undue abrasion and wear on the grenade rifle rifling. It is also desirable to use a material with more structural integrity, and/or one that is less expensive, for the rest of the sabot. The material chosen for the drive lands may also be selected to avoid or minimize the likelihood of leaving a streak of drive lands material in the rifling through repeated firing of grenades.

Preferably the material chosen for the drive lands is selected for its heat resistance, its lubricity, its ability to resist smearing in the rifling, and its stability. As indicated, it has been found that Teflon works well for the drive lands with at least some embodiments of the invention, although it should be appreciated that many alternative materials will also function satisfactorily.

It should also be appreciated that the concept of forming drive lands from a dissimilar material to the rest of the sabot can be employed with other types of grenades, for example those having a combat payload rather than only a dye. For example, the drive lands concept may be used with a grenade where the combat payload is a plurality of projectiles—ie as with published New Zealand patent specification No. 514921. Alternatively the concept may be used with a grenade where the payload is a quantity of explosive material, or a gas (eg tear gas), etc.

While some preferred forms of the invention have been described by way of example it should be appreciated that improvements and modifications can occur without departing from the scope of the appended claims. 

1. A grenade comprising a case, a sabot, and a forward part incorporating a pay load, the case incorporating a suitable firing charge, the sabot having a projection or projections on its periphery arranged to engage rifling in the barrel of a grenade firing weapon when the grenade is being fired so that such engagement imparts spin to the sabot; the grenade being characterized in that the projection or projections is/are formed from a suitable synthetic substance substantially different to the substance used to form the periphery of the sabot from which the projection(s) extend.
 2. A grenade according to claim 1, wherein the projection or projections on the one hand, and the rest of the sabot on the other, are formed each from a dissimilar polymeric substance.
 3. A grenade according to claim 1, wherein the projection or projections are substantially formed from Teflon.
 4. A grenade according to claim 1, wherein the projection or projections on the one hand, and the rest of the sabot on the other, are formed each from a dissimilar polymeric substance, and wherein the payload is selected from at least one of a quantity of dye, a plurality of projectiles, and an explosive.
 5. A grenade according to claim 1 wherein the forward part is snap fitted to the sabot.
 6. A grenade according to claim 1 wherein the case is snap fitted to the sabot.
 7. A grenade according to claim 1, wherein the forward part comprises a nose cone.
 8. A grenade comprising a case, a sabot, and a forward part in the form of a nose cone incorporating a pay load, the case incorporating a suitable firing charge, the sabot and the forward part being snap fitted to one another, and the sabot having a projection or projections on its periphery arranged to engage rifling in the barrel of a grenade firing weapon when the grenade is being fired so that such engagement imparts spin to the sabot; the grenade being characterized in that the projection or projections is/are formed from a suitable synthetic substance substantially different to the substance used to form the periphery of the sabot from which the projection(s) extend.
 9. A grenade according to claim 8, wherein the projection or projections are substantially formed from a suitable synthetic substance.
 10. A grenade according to claim 9, wherein the projection or projections are substantially formed from Teflon. 